defconfig: arm64: msmcortex: Enable IIO and RRADC driver

Enable Round robin ADC (RRADC) driver to enable clients
to read channels on pmicobalt such as battery ID, battery
thermistors. Enable IIO since RRADC driver registers with
the IIO framework and clients can use the IIO
framework to issue read requests for supported
RRADC channels.

Change-Id: I88b5922ab4dc817257042fdaa385768e6f14be57
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>